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| author | Chris Mason <chris.mason@oracle.com> | 2008-11-10 11:44:58 -0500 |
|---|---|---|
| committer | Chris Mason <chris.mason@oracle.com> | 2008-11-10 11:44:58 -0500 |
| commit | e04ca626baee684bea9d6239e4e1119b696101b2 (patch) | |
| tree | f5327eae3e8393f19ef9f40426efb8b3488f36f6 /fs/btrfs/compression.c | |
| parent | ff5b7ee33d82414bf4baf299c21fb703bcc89629 (diff) | |
| download | linux-e04ca626baee684bea9d6239e4e1119b696101b2.tar.bz2 | |
Btrfs: Fix use after free during compressed reads
Yan's fix to use the correct file offset during compressed reads used the
extent_map struct pointer after it had been freed. This saves the
fields we want for later use instead.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
Diffstat (limited to 'fs/btrfs/compression.c')
| -rw-r--r-- | fs/btrfs/compression.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c index 8e7a78acf81a..b582c6fd80f2 100644 --- a/fs/btrfs/compression.c +++ b/fs/btrfs/compression.c @@ -505,6 +505,8 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, struct block_device *bdev; struct bio *comp_bio; u64 cur_disk_byte = (u64)bio->bi_sector << 9; + u64 em_len; + u64 em_start; struct extent_map *em; int ret; @@ -525,7 +527,10 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, cb->start = em->orig_start; compressed_len = em->block_len; + em_len = em->len; + em_start = em->start; free_extent_map(em); + em = NULL; cb->len = uncompressed_len; cb->compressed_len = compressed_len; @@ -543,7 +548,7 @@ int btrfs_submit_compressed_read(struct inode *inode, struct bio *bio, } cb->nr_pages = nr_pages; - add_ra_bio_pages(inode, em->start + em->len, cb); + add_ra_bio_pages(inode, em_start + em_len, cb); if (!btrfs_test_opt(root, NODATASUM) && !btrfs_test_flag(inode, NODATASUM)) { |